1. Field of the Invention
The present invention relates to structures for non-pneumatically actuated accumulation conveyors, as well as methods of using narrow belt accumulation conveyors. Generally, accumulation conveyors include numerous zones of item transporting rollers. Dependent upon predetermined paradigms, any zone of item transporting rollers can be dormant or activated. Engagement of the narrow belt with the underneath side of the zone""s item transporting rollers moves goods along the topside of activated zone""s item transporting rollers. More specifically, the present accumulator utilizes a non-pneumatically actuated assembly to shift the narrow belt into engagement with the underneath side of the item transporting rollers. In select embodiments, an electric actuator lifts the assembly""s rack journaling a plurality of pressure rollers to contact the narrow belt and force the belt into engagement with the underneath side of the item transporting rollers. Certain embodiments can also journal a pivoting tracking roller in the assembly""s rack to center the sideways movement of the belt. Other embodiments have flanged pressure rollers to center the narrow belt as it moves about the assembly""s rack. And still other embodiments utilize a combination of flanged pressure rollers and a pivoting tracking roller to center sideways movement of the belt as it travels about the accumulation conveyor. Other embodiments incorporate a constant force takeup for the belt.
2. Description of the Previous Art
a) U.S. Pat. No. 4,609,098-Morgan, et. al. enables pneumatic controls for the modular components of an accumulation conveyor. Each modular zone includes a rack or bar (30) positioned beneath the movable slide plates (22) of the rollers (20). The racks (30) are mounted on compressed air cylinders (31) and (32). And the belt (12) is centered by alternating the movable ends of rollers (20) from zone to zone. The ""098 Patent requires pressure rollers 20 to extend across the width of the conveyor.
b) U.S. Pat. No. 5,862,907-Taylor describes a control module for an accumulation conveyor. Each module""s casing (24) is mounted to the side rail of the Taylor conveyor, and each module has a sensor disposed to one side. The ""907 module""s logic circuitry may include a microprocessor, and Taylor""s sensors can be photoelectric, proximity or ultrasonic. Although a specific driving force is not disclosed, Taylor uses a pneumatically actuated solenoid to engage his driving force.
c) U.S. Pat. No. 6,065,588-Cotter, et. al., enables a contact assembly for accumulation conveyors. Endless drive member (30) is positioned proximate to either side rail (20) or side rail (22), and the drive member (30) drives Cotter""s conveying rollers. Each zone of the accumulation conveyor (10) has as least one contact assembly (50) juxtaposed with the upper portion (31) of drive belt (30) beneath the conveying rollers (25). The ""588 contact assembly (50) includes support member (60) that is mounted to rail (20). Importantly, contact assembly (50) has a pneumatic block (90). Thus, compressed air vertically reciprocates platform (82).
Cotter""s support member (60) has a horizontal surface (70) extending from back (64). The horizontal surface (70) is formed to have a cavity (72) that is configured to retainably receive the pneumatic diaphragm. Guide members (75) support contact member (79) enabling its vertical reciprocation with respect to support member (60). Significantly, the ""588 contact member (79) includes a platform (80) that has a pair of contact rollers (84) and (86) for connecting with the upper portion (31) of drive belt (30). Cotter""s arm (124) extends from side (100) and beyond end (104) of platform (80) while arm (134) extends from side (102) and beyond end (106) of platform (80). Finally, because shafts (128) and (138) extend in opposite directions, contact rollers (84) and (86) are jounaled at opposite ends of platform (80).
d) U.S. patent application No. 2001/0004959A1-Cotter, et. al. discloses a contact assembly for accumulation conveyors. Cotter utilizes a pivoting platform to support his contact rollers. In one embodiment contact rollers (84) and (86) are crowned so that when drive member (30) becomes misaligned, the crowned surface will attempt to bring endless drive member (30) into alignment with contact member (30). Since contact member 79 is capable of pivoting about post (75xe2x80x2), the force created between endless drive member (30) and the contact roller will tend to laterally move contact member (79). And when endless drive member (30) becomes more extensively misaligned along contact rollers (84) and (86), endless drive member (30) will contact one of the pair of out-turned flanges (85) located at opposing ends of first contact roller (84).
In another embodiment of the Cotter contact assembly, contact between protrusion (162) and contact rollers (186a, 186b) rotates platform (170) about the vertical axis of guide member (206). A widened channel of post (203) enables platform (200) to maintain the alignment between the first pair of contact rollers (186), second pair of contact rollers (188), and the endless drive member (160.)
e) U.S. Pat. No. 5,429,225-Schiesser, et. al., enables a modular pneumatic accumulation conveyor. More specifically, the ""225 actuator is mechanically coupled to the product sensor (42). Schiesser""s pneumatic actuator (38) is activated when his product sensor detects product, and causes the contact member (78) to interface with the upper portion (40) of drive belt (36).
f) U.S. patent application No. 2002/0092736A1-Masuda appears to disclose a device for transmitting motion to the rollers of a conveyor. In part, Paragraphs 32 and 34 of the Application read: xe2x80x9cAn actuator 17 (referring FIG. 3) making the bearing 13 swung, arranged to be located in the right of the lower part of the bearing 13, is installed on the inner side surface of the right side wall 3. This structure makes the transmission roller 14 and the driven wheel 15 located in one side of the bearing 13 and also makes the actuator 17 located in the other side of the bearing 13. By the structure like this, as the transmission roller 14 is contacted with the roller 6 by swinging the transmission roller 14 side upward . . . xe2x80x9d
g) U.S. Pat. No. 6,193,054B1-Henson, et. al., discloses a modular accumulator conveyor system. The Henson actuator assembly (32) and its pneumatic motor (33) are positioned directly under the drive belt (20) while the 054"" actuator (32) is operated by control valve (34). Finally, the upward driving run (25) is lifted upward by the pressure roller (13) mounted in the cradle (31).
h) U.S. Pat. No. 6,035,998-Garzelloni teaches a pneumatic device (20) for lifting a plurality of lifting rollers (16) that are mounted in the side channels of the frame (11) beneath the carrier rollers (14).
i) U.S. Pat. No. 5,540,323-Schiesser, et. al., teaches a pneumatic accumulation conveyor. Schiesser""s contact member does not contain any rollers for engaging the driving belt. Instead, the ""323 pneumatic actuator causes the low-friction slider surface of the contact member to interface with upper portion (40) of drive belt (36) such that the belt is lifted into engagement with rollers (30) adjacent the actuator (38). The Schiesser actuator (38) is juxtaposed with the upper portion (40) of drive belt (36), and a product sensor (42) is provided for each conveyor zone to control the actuators.
j) U.S. Pat. No. 5,906,267-Heit, et. al., enables a pneumatically actuated zero pressure accumulation conveyor. The ""267 Patent discloses that pneumatic pressure expands bladder (64) to lift channel (46) and the upper run (24) relative to the rollers (18).
k) U.S. Pat. No. 4,919,255-Morgan, et. al. is a continuation application Patent flowing from the U.S. Pat. No. 4,609,098-Morgan, et. al. Patent.
l) U.S. Pat. No. 5,191,967-Woltjer, et. al., defines a conveyor system having a non-singulating accumulation conveyor. Each Woltjer zone (38) has a drive belt assembly that uses a pneumatic diaphragm (44) to cause the padded chain (42 ) to engage the conveyor""s rollers (34). The ""967 photodetectors provide for xe2x80x9czero pressurexe2x80x9d actuation of the conveying rollers.
m) U.S. Pat. No. 5,823,319-Resnick, et. al. discloses the use of friction wheels (72) to drive rollers (74) of the ""319 accumulating conveyor.
n) U.S. Pat. No. 4,345,684-Rolland teaches an accumulator conveyor utilizing a central beam (4) that supports rotors (6) for applying the drive belt (7) to be brought into a friction drive relationship with the carrier rollers (3) above the rotors (6).
o) U.S. Pat. No. 4,108,304-McKnight, et. al., enables a powered roller accumulation conveyor.
Unlike traditional zone accumulation conveyors, the present invention utilizes a rack for journaling the pressure roller or rollers. Instead of pneumatic actuators, commonly used in the industry, an electric actuator, e.g., an electric motor or a solenoid, urges the narrow belt traveling over or about the pressure rollers journaled in the rack into the underneath side of the corresponding zone""s item transporting rollers. With the elimination of air compressors, lines, tubing, et cetera, associated with conventional pneumatically actuated accumulators, costs of construction are reduced.
Due to the electric actuation of assemblies carrying the rack, the numbers of zones of item transporting rollers are only limited by space for and use of the accumulator. Thus, in select embodiments, an accumulator including multiple zones of item carrying rollers is contemplated. And as another feature of the present invention, the logical paradigm allows for simultaneous activation of one or more zones of item transporting rollers.
Movable linkage or linkages or supports mounted to the accumulation conveyor""s frame carry each zone""s rack. The rack""s length can approximate the length of its corresponding zone of item transporting rollers. In some embodiments, the actuation assembly""s actuator""s arm is received by an aperture of the rack""s sidewall, while in other embodiments, the arm includes an offset shaft.
Upon activation of the actuator""s arm, the rack is lifted vertically. Because of the movable linkage or support, the upper side of the rack remains in a substantially parallel relationship with the underneath side of its corresponding zone""s item transporting rollers. In another unique feature, each actuator can be provided with a microprocessor or other type of controller located on or about the actuator. Via a logic circuit, the controllers or microprocessors of each zone communicate with their immediate upstream and/or downstream controllers or microprocessors. And depending upon predetermined parameters, each zone""s microprocessor can communicate with all upstream and/or downstream zones"" microprocessors.
Other embodiments of the present invention can include a pivoting tracking roller journaled in the rack as well as a constant force takeup for the belt. It has been determined that the pivoting tracking roller tends to center the narrow belt as it traverses the pressure roller or rollers. The constant force takeup adjusts the tension applied to the accumulation conveyor""s belt, as the belt winds about the accumulator. Still other embodiments can utilize flanged pressure rollers alone or in combination with the pivoting tracking rollers to center the narrow belt as it rotates about the accumulation conveyor.
An object of the present invention is to provide an non-pneumatically actuated zone accumulation conveyor.
It is another object of the present invention to enable a method of using the non-pneumatically actuated zone accumulation conveyor.
Still another object of the present invention is to eliminate air compressors, pneumatic tubing, conduits, et cetera, associated with heretofore conventional accumulation conveyors.
Yet another object of the present invention is to enable an electrically actuated rack carrying a pressure roller or pressure rollers for use with zone accumulation conveyors.
Still another object of the present invention is to provide a controller or microprocessor positioned on or about an electric actuator or actuators of zone accumulation conveyors.
Yet still another object of the present invention is to utilize the invention""s inactive mode to conserve energy consumption.
It is yet another object of the present invention to reduce noise output of the zone accumulation conveyor.
Still another object of the present invention is to provide a constant force takeup for the belt.
An object of an embodiment of the present invention is to incorporate a constant force spring takeup into the accumulation conveyor""s drive unit.
An object of another embodiment of the present invention is to incorporate a pivoting tracking roller into the rack of a zone accumulation conveyor.
An object of an embodiment of the present invention is to journal one or more flanged pressure rollers in the rack to assist in centering the narrow belt as it travels about the accumulation conveyor.
An object of still another embodiment of the present invention to incorporate a rack utilizing a combination of a flanged pressure roller or rollers and a pivoting tracking roller to assist in centering the narrow belt as it travels about the accumulation conveyor.
An embodiment of the present invention can be described as an assembly for imparting rotation to a zone of item transporting rollers of an accumulation conveyor, comprising: a first linkage connected at a first location of a frame""s side rail; an electric actuator, including an arm for generating vertical movement; a vertically movable rack, approximating the length of the zone, wherein the vertically movable rack receives the arm; a plurality of rollers jounaled in the vertically movable rack; and a controller for the electric actuator. In select embodiments, the assembly""s actuator can also include a microprocessor and an offset arm.
Another embodiment of the present apparatus can be described as a non-pneumatically actuated assembly for imparting rotation to a zone of item transporting rollers of an accumulation conveyor, comprising: a first vertically movable support and a non-pneumatic actuator, including a vertically movable arm, mounted to the frame of the accumulation conveyor; a rack having an upper side substantially parallel to an underneath the zone of item transporting rollers, wherein the rack receives the arm and is connected to the first vertically movable support; a plurality of rollers channeled in said rack; an idler roller; and a controller for said non-pneumatic actuator for causing the belt to engage or disengage the underneath side of the item transporting rollers.
Yet another embodiment of the present invention can be described as an accumulation conveyor comprising: a plurality of zones of item transporting rollers; a drive for a belt for imparting rotation to the item transporting rollers; a constant force take-up for the belt; a frame holding each zone of item transporting rollers; a plurality of idler rollers; an item detecting sensor for each zone of item transporting rollers; a stationary, upward or downward movable assembly for each zone, wherein each stationary, upward or downward movable assembly is located beneath its corresponding zone of item transporting rollers, and wherein the movable assembly further comprises: a first substantially vertically movable linkage mounted to the frame, an electric actuator, including an arm for generating vertical movement, and a rack connected with the first substantially vertically movable linkage, wherein the rack journals a plurality of pressure rollers; and a controller for controlling the movable assembly in accordance with a preprogrammed paradigm.
In still another embodiment, the present invention can be described as a method of imparting rotation to a zone of item transporting rollers of an accumulation conveyor comprising the steps of: mounting an assembly, including a rack, to a frame of the accumulation conveyor such that the rack is vertically movable; journaling a plurality of pressure rollers in the rack; driving a belt about the plurality of pressure rollers and a plurality of idler rollers; applying a constant take-up force to the belt; journaling a pivoting tracking roller in the rack; positioning an item sensor in the zone; connecting the item sensor to a microprocessor located on or about an electric actuator; joining the electric actuator with the rack; and electrically actuating the rack.
Yet still another embodiment can be described as a method of imparting rotation to item transporting rollers, comprising the steps of: establishing an accumulation conveyor comprising a plurality of zones of said item transporting rollers; journaling a plurality of pressure rollers in a plurality of racks; assembling one of the racks about each said zone of item transporting rollers; driving a belt about the pressure rollers and a plurality of idler rollers; applying a constant take-up force to the belt; positioning an item sensor in each zone; providing an electric actuator for each of the racks, wherein the electric actuator further comprises a microprocessor; linking the microprocessor of each of the electric actuators with at least its upstream zone""s microprocessor or its downstream zone""s microprocessor; linking each microprocessor with its corresponding sensor; and actuating one or more of the racks, according to a predetermined paradigm, wherein any actuated rack shifts the belt driven about the actuated rack to engage the actuated rack""s corresponding zone of item transporting rollers.
It is the novel and unique interaction of these simple elements which creates the apparatus and methods, within the ambit of the present invention. Pursuant to Title 35 of the United States Code, descriptions of preferred embodiments follow. However, it is to be understood that the best mode descriptions do not limit the scope of the present invention.